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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,189 records · Page 66
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Rocket propulsion by thermonuclear micro-bombs ignited with intense relativistic electron beams.

Discussion of a method for the ignition of a thermonuclear microbomb by means of an intense relativistic electron beam with regard to its potential application to rocket propulsion. With such a system, exhaust velocities up to 1000 km/sec, corresponding to a specific impulse of 100,000 sec, seem to be within the realm of possibility. The rocket is propelled by a chain of thermonuclear microbombs exploded in a concave magnetic mirror produced by superconducting field coils. The magnetic pressure of the field reflects the fireball generated by the explosion. For the large capacitor bank required to generate the intense relativistic electron beam, a desirable lightweight design may be possible through use of ferroelectric materials. Because of the high cost of the T-D and He 3-D thermonuclear material, the system has to be optimized by minimizing the T-D and He 3-D consumption by a proper TD and He 3-D fuel to hydrogen propellant mass ratio, leading to a larger total system mass than would be absolutely necessary.

Winterberg, F.↗
NASA NTRS1973

Measuring micro-organism gas production

Transducer, which senses pressure buildup, is easy to assemble and use, and rate of gas produced can be measured automatically and accurately. Method can be used in research, in clinical laboratories, and for environmental pollution studies because of its ability to detect and quantify rapidly the number of gas-producing microorganisms in water, beverages, and clinical samples.

Wilkins, J. R.↗
NASA NTRS1975

Micro-organism distribution sampling for bioassays

Purpose of sampling distribution is to characterize sample-to-sample variation so statistical tests may be applied, to estimate error due to sampling (confidence limits) and to evaluate observed differences between samples. Distribution could be used for bioassays taken in hospitals, breweries, food-processing plants, and pharmaceutical plants.

Nelson, B. A.↗
NASA NTRS1974

Evaluation report for toggle switches: Micro Switch and Cutler-Hammer models per MIL-S-3950

Several models of hermetically sealed toggle switches meeting the requirements of MIL-S-3950, were evaluated to determine the probability that they would withstand the environmental requirements of, and therefore be suitable for use on, the space shuttle vehicle. The evaluation was started with a comparison of the environmental requirements for space shuttle hardware. This was followed with in-house testing for those environments where a reasonably firm conclusion could not be drawn in the comparison. Space simulation, acceleration, and vibration testing were performed in-house.

Labberton, D.↗
NASA NTRS1973

Polarized crystal-field spectra of micro particles of the moon

The instrumentation used in the investigation is considered, giving attention also to a block diagram of the apparatus used for measuring crystal-field spectra. The basic object of the studies was to identify the states of transition elements in lunar crystals in order to obtain information on the chemistry of their crystallization history. After spectral measurements were obtained, the crystals were analyzed for major and minor elements using the electron microprobe. Mineral spectra are considered, giving attention to pyroxene, olivine, plagioclase, and lunar glasses.

Mao, H. K.↗
NASA NTRS1976

Accelerated test techniques for micro-circuits: Evaluation of high temperature (473 k - 573 K) accelerated life test techniques as effective microcircuit screening methods

The application of high temperature accelerated test techniques was shown to be an effective method of microcircuit defect screening. Comprehensive microcircuit evaluations and a series of high temperature (473 K to 573 K) life tests demonstrated that a freak or early failure population of surface contaminated devices could be completely screened in thirty two hours of test at an ambient temperature of 523 K. Equivalent screening at 398 K, as prescribed by current Military and NASA specifications, would have required in excess of 1,500 hours of test. All testing was accomplished with a Texas Instruments' 54L10, low power triple-3 input NAND gate manufactured with a titanium- tungsten (Ti-W), Gold (Au) metallization system. A number of design and/or manufacturing anomalies were also noted with the Ti-W, Au metallization system. Further study of the exact nature and cause(s) of these anomalies is recommended prior to the use of microcircuits with Ti-W, Au metallization in long life/high reliability applications. Photomicrographs of tested circuits are included.

Johnson, G. M.↗
NASA NTRS1975

Application of a dedicated micro-processor for automatic data acquisition of load strain and acoustic-emission data

This paper describes an automatic system for acquisition, logging and analysis of stress, strain and acoustic emission data. The complete system is a combination of several standard items of equipment and a newly developed intelligent data logger which has the capability to send data directly to a large scale computer for reduction and plotting. The data logging and all interfacing with peripheral equipment are accomplished using digital electronics. The heart of the system is a four-bit microprocessor and digital cassette tape unit. The system, which is controlled by instructions from a cathode ray tube terminal, has the capability to transmit data from the cassette unit to a large computer via a time sharing option. Typical results are presented for acoustic emission count rate and total count curves superimposed on stress-strain diagrams for boron/epoxy advanced composites.

Wilson, G. H.↗
NASA NTRS1975

An impact analysis of a micro wind system

A process for the recovery of steel mill stack dust has been developed and is being used to recover secondary metals by a small company in Georgia. The process is energy intensive and wind generators were studied as a means of supplying energy for part of the recovery process. Some of the results of this study will be presented.

Zimmer, R. P.↗
NASA NTRS1979

Identification of micro-organisms

Manual presents detailed laboratory procedures for identifying aerobic or microaerobic bacteria, yeast or yeastible organisms, and filamentous fungi and conducting other microbiological or immunological evaluations of samples taken from human subjects. Standardized procedures should be useful to researchers and clinicians in laboratories, hospitals and other biological test facilities.

Taylor, G. R.↗
NASA NTRS1980

The role of the micro environment on the tribological behavior of materials

The properties of the environment which exert an influence upon adhesion, friction, wear, and lubrication of materials in solid state contact are discussed. The effect of the environment upon lubricants and lubricant properties is considered in relation to the interaction of the lubricant with the material surfaces in solid state contact and the ability of lubricants to provide protective surface films.

Buckley, D. H.↗
NASA NTRS1980

Micro-fluid exchange coupling apparatus

In a macro-fluid exchange, a hollow needle, such as a syringe needle, is provided for penetrating the fluid conduit of the animal. The syringe needle is coupled to a plenum chamber having an inlet and outlet port. The plenum chamber is coupled to the syringe needle via the intermediary of a standard quick disconnect coupling fitting. The plenum chamber is carried at the end of a drive rod which is coupled to a micrometer drive head. The micrometer drive head is slidably and pivotably coupled to a pedestal for adjusting the height and angle of inclination of the needle relative to a reference base support. The needle is positioned adjacent to the incised trachea or a blood vessel of a small animal and the micrometer drive head is operated for penetrating the fluid conduit of the animal.

Johnson, J. E., Jr.↗
NASA NTRS1980

The role of the micro environment on the tribological behavior of materials

The paper reviews studies of the role of the microenvironment in the adhesion, friction, and wear behavior of materials in solid-state contact. The microenvironment is defined as the environment on the surface of solids in solid-state contact. Properties of the environment are discussed which exert an influence on the adhesion, friction, wear, and lubrication of materials in contact. The effect of the environment on lubricants and their properties is considered with respect to the interaction of lubricants with material surfaces in contact; the effect on the ability of lubricants to provide protective surface films is also considered. It is concluded that naturally occurring oxides are probably the best available natural solid-film lubricants.

Buckley, D. H.↗
NASA NTRS1981

Cavity-backed, micro-strip dipole antenna array

A flush-mounted antenna assembly includes a generally rectangular, conductive, box structure open along one face to form a cavity. Within the cavity a pair of mutually orthogonal dielectric plane surfaces in an "egg crate" arrangement are mounted normal to the plane of the open face, each diagonally within the cavity. Each dielectric plane supports a pair of printed circuit dipoles typically each fed from the opposite side of the dielectric plane by a printed "cone-shaped" feed line trace which also serve as an impedance matching device and functions as a balun connected from an unbalanced strip line external feed. The open face of the conductive cavity can be flush mounted with a randome thereover, the assembly thereby being flush with the skin of a aircraft or space vehicle.

Ellis, H., Jr.↗
NASA NTRS1981

Development and implementation of a low cost micro computer system for LANDSAT analysis and geographic data base applications

Since the implementation of the GRID and IMGRID computer programs for multivariate spatial analysis in the early 1970's, geographic data analysis subsequently moved from large computers to minicomputers and now to microcomputers with radical reduction in the costs associated with planning analyses. Programs designed to process LANDSAT data to be used as one element in a geographic data base were used once NIMGRID (new IMGRID), a raster oriented geographic information system, was implemented on the microcomputer. Programs for training field selection, supervised and unsupervised classification, and image enhancement were added. Enhancements to the color graphics capabilities of the microsystem allow display of three channels of LANDSAT data in color infrared format. The basic microcomputer hardware needed to perform NIMGRID and most LANDSAT analyses is listed as well as the software available for LANDSAT processing.

Faust, N.↗
NASA NTRS1983

Tectonic deformation of the Andes and the configuration of the subducted slab in central Peru: Results from a micro-seismic experiment

The vast majority of the microearthquakes recorded occurred to the east: on the Huaytapallana fault in the Eastern Cordillera or in the western margin of the sub-Andes. The sub-Andes appear to be the physiographic province subjected to the most intense seismic deformation. Focal depths for the crustal events here are as deep as 50 km, and the fault plane solutions, show thrust faulting on steep planes oriented roughly north-south. The Huaytapallana fault in the Cordillera Oriental also shows relatively high seismicity along a northeast-southwest trend that agrees with the fault scarp and the east dipping nodal plane of two large earthquakes that occurred on this fault in 1969. The recorded microearthquakes of intermediate depth show a flat seismic zone about 25 km thick at a depth of about 100 km. This agrees with the suggestion that beneath Peru the slab first dips at an angle of 30 deg to a depth of 100 km and then flattens following a quasi-horizontal trajectory. Fault plane solutions of intermediate depth microearthquakes have horizontal T axes oriented east-west.

Suarez, G.↗